He said in a new blog post on Sunday night that he "took one for the team" by pleading guilty to misdemeanor charges in what police said was a brutal attack on a girlfriend last August, yet the board betrayed him and demanded he resign. Chahal later deleted the blog.

"Is this what real entrepreneurism is about? Is this what venture capitalism is about?" he wrote. "Not to forget, in my last startup I made these same individuals over 800 percent on their investment? Whatever happened to real ethics? What happened to integrity? Whatever happened (to) supporting your CEO during the tough times knowing the truth? Or is just a fabrication of today’s society of greed at all costs (sic)."

The board did not specifically say why it fired Chahal in a brief statement issued on Sunday in which it announced that he had been replaced as CEO by Chief Operating Officer Bill Lonergan. They have not responded to requests for interviews about the situation.

Chahal, though, included in his blog what he said is the text of a supportive email from one of the board members after he agreed to pay a $500 fine, probation and domestic abuse counseling.

He says Robin Murray of Adams Street Partners wrote: "Been thinking some more. Absolutely don’t do anything. Let the haters hate and move on. This will blow over very quickly and we focus on the IPO. Don’t let them get to you. Don’t respond. I know it sucks but i think this is the right way fwd. Stay strong amigo. I feel for you."

Chahal didn't quote any of the other board members — former California State Controller Steve Westly, Ajay Chopra of Trinity Ventures and David Silverman of Crosslink Capital — but he described them as being "ecstatic" that they could move on with IPO plans after the charges were settled.

Chahal said support from the board crumbled when pressure mounted for it to act.

He didn't repeat his claim that he is still CEO of RadiumOne, something he said in an earlier blog on Sunday that was posted after he had been fired.

Therefore, it remains unclear whether he intends to continue to fight to keep control of the San Francisco ad tech company in which he reportedly still has a very large stake.

What is clear, though, is that he is unrepentant about the situation and isn't afraid to drag others down with him.